add option for stripping EXIF data on image/video uploads

[Ember-ruby]

as EXIF data can be quite dangerous (e.g. can dox you), adding an option to automatically strip it would be great (or have a checkbox you can check to strip it)

i understand if this is out of scope, as microbin isn't primarily for sharing images, but i think it would be helpful

[albocc]

If somebody wants to implement this, I would like to add that this option should be a choice (potentially with a default provided as a program argument) at upload time. EXIF data can provide useful information that the uploader might want to preserve.